1 files changed, 312 insertions, 161 deletions

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 2bf27f364d0..0c27ed6f3f2 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
+#include <linux/elf.h>
 #include <linux/smp.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
@@ -21,11 +22,17 @@
 #include <linux/uaccess.h>
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
+#include <linux/regset.h>
+#include <linux/audit.h>
+#include <linux/tracehook.h>
+#include <linux/unistd.h>
 
 #include <asm/pgtable.h>
-#include <asm/system.h>
 #include <asm/traps.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
 #define REG_PC	15
 #define REG_PSR	16
 /*
@@ -227,34 +234,12 @@ static struct undef_hook thumb_break_hook = {
 	.fn		= break_trap,
 };
 
-static int thumb2_break_trap(struct pt_regs *regs, unsigned int instr)
-{
-	unsigned int instr2;
-	void __user *pc;
-
-	/* Check the second half of the instruction.  */
-	pc = (void __user *)(instruction_pointer(regs) + 2);
-
-	if (processor_mode(regs) == SVC_MODE) {
-		instr2 = *(u16 *) pc;
-	} else {
-		get_user(instr2, (u16 __user *)pc);
-	}
-
-	if (instr2 == 0xa000) {
-		ptrace_break(current, regs);
-		return 0;
-	} else {
-		return 1;
-	}
-}
-
 static struct undef_hook thumb2_break_hook = {
-	.instr_mask	= 0xffff,
-	.instr_val	= 0xf7f0,
+	.instr_mask	= 0xffffffff,
+	.instr_val	= 0xf7f0a000,
 	.cpsr_mask	= PSR_T_BIT,
 	.cpsr_val	= PSR_T_BIT,
-	.fn		= thumb2_break_trap,
+	.fn		= break_trap,
 };
 
 static int __init ptrace_break_init(void)
@@ -276,7 +261,7 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 {
 	unsigned long tmp;
 
-	if (off & 3 || off >= sizeof(struct user))
+	if (off & 3)
 		return -EIO;
 
 	tmp = 0;
@@ -288,6 +273,8 @@ static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
 		tmp = tsk->mm->end_code;
 	else if (off < sizeof(struct pt_regs))
 		tmp = get_user_reg(tsk, off >> 2);
+	else if (off >= sizeof(struct user))
+		return -EIO;
 
 	return put_user(tmp, ret);
 }
@@ -308,58 +295,6 @@ static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
 	return put_user_reg(tsk, off >> 2, val);
 }
 
-/*
- * Get all user integer registers.
- */
-static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
-{
-	struct pt_regs *regs = task_pt_regs(tsk);
-
-	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
-}
-
-/*
- * Set all user integer registers.
- */
-static int ptrace_setregs(struct task_struct *tsk, void __user *uregs)
-{
-	struct pt_regs newregs;
-	int ret;
-
-	ret = -EFAULT;
-	if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
-		struct pt_regs *regs = task_pt_regs(tsk);
-
-		ret = -EINVAL;
-		if (valid_user_regs(&newregs)) {
-			*regs = newregs;
-			ret = 0;
-		}
-	}
-
-	return ret;
-}
-
-/*
- * Get the child FPU state.
- */
-static int ptrace_getfpregs(struct task_struct *tsk, void __user *ufp)
-{
-	return copy_to_user(ufp, &task_thread_info(tsk)->fpstate,
-			    sizeof(struct user_fp)) ? -EFAULT : 0;
-}
-
-/*
- * Set the child FPU state.
- */
-static int ptrace_setfpregs(struct task_struct *tsk, void __user *ufp)
-{
-	struct thread_info *thread = task_thread_info(tsk);
-	thread->used_cp[1] = thread->used_cp[2] = 1;
-	return copy_from_user(&thread->fpstate, ufp,
-			      sizeof(struct user_fp)) ? -EFAULT : 0;
-}
-
 #ifdef CONFIG_IWMMXT
 
 /*
@@ -418,56 +353,6 @@ static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
 }
 #endif
 
-#ifdef CONFIG_VFP
-/*
- * Get the child VFP state.
- */
-static int ptrace_getvfpregs(struct task_struct *tsk, void __user *data)
-{
-	struct thread_info *thread = task_thread_info(tsk);
-	union vfp_state *vfp = &thread->vfpstate;
-	struct user_vfp __user *ufp = data;
-
-	vfp_sync_hwstate(thread);
-
-	/* copy the floating point registers */
-	if (copy_to_user(&ufp->fpregs, &vfp->hard.fpregs,
-			 sizeof(vfp->hard.fpregs)))
-		return -EFAULT;
-
-	/* copy the status and control register */
-	if (put_user(vfp->hard.fpscr, &ufp->fpscr))
-		return -EFAULT;
-
-	return 0;
-}
-
-/*
- * Set the child VFP state.
- */
-static int ptrace_setvfpregs(struct task_struct *tsk, void __user *data)
-{
-	struct thread_info *thread = task_thread_info(tsk);
-	union vfp_state *vfp = &thread->vfpstate;
-	struct user_vfp __user *ufp = data;
-
-	vfp_sync_hwstate(thread);
-
-	/* copy the floating point registers */
-	if (copy_from_user(&vfp->hard.fpregs, &ufp->fpregs,
-			   sizeof(vfp->hard.fpregs)))
-		return -EFAULT;
-
-	/* copy the status and control register */
-	if (get_user(vfp->hard.fpscr, &ufp->fpscr))
-		return -EFAULT;
-
-	vfp_flush_hwstate(thread);
-
-	return 0;
-}
-#endif
-
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 /*
  * Convert a virtual register number into an index for a thread_info
@@ -497,7 +382,7 @@ static long ptrace_hbp_idx_to_num(int idx)
 /*
  * Handle hitting a HW-breakpoint.
  */
-static void ptrace_hbptriggered(struct perf_event *bp, int unused,
+static void ptrace_hbptriggered(struct perf_event *bp,
 				     struct perf_sample_data *data,
 				     struct pt_regs *regs)
 {
@@ -580,7 +465,8 @@ static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 	attr.bp_type	= type;
 	attr.disabled	= 1;
 
-	return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, tsk);
+	return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
+					   tsk);
 }
 
 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
@@ -694,6 +580,221 @@ out:
 }
 #endif
 
+/* regset get/set implementations */
+
+static int gpr_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   void *kbuf, void __user *ubuf)
+{
+	struct pt_regs *regs = task_pt_regs(target);
+
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				   regs,
+				   0, sizeof(*regs));
+}
+
+static int gpr_set(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct pt_regs newregs;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &newregs,
+				 0, sizeof(newregs));
+	if (ret)
+		return ret;
+
+	if (!valid_user_regs(&newregs))
+		return -EINVAL;
+
+	*task_pt_regs(target) = newregs;
+	return 0;
+}
+
+static int fpa_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   void *kbuf, void __user *ubuf)
+{
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				   &task_thread_info(target)->fpstate,
+				   0, sizeof(struct user_fp));
+}
+
+static int fpa_set(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   const void *kbuf, const void __user *ubuf)
+{
+	struct thread_info *thread = task_thread_info(target);
+
+	thread->used_cp[1] = thread->used_cp[2] = 1;
+
+	return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+		&thread->fpstate,
+		0, sizeof(struct user_fp));
+}
+
+#ifdef CONFIG_VFP
+/*
+ * VFP register get/set implementations.
+ *
+ * With respect to the kernel, struct user_fp is divided into three chunks:
+ * 16 or 32 real VFP registers (d0-d15 or d0-31)
+ *	These are transferred to/from the real registers in the task's
+ *	vfp_hard_struct.  The number of registers depends on the kernel
+ *	configuration.
+ *
+ * 16 or 0 fake VFP registers (d16-d31 or empty)
+ *	i.e., the user_vfp structure has space for 32 registers even if
+ *	the kernel doesn't have them all.
+ *
+ *	vfp_get() reads this chunk as zero where applicable
+ *	vfp_set() ignores this chunk
+ *
+ * 1 word for the FPSCR
+ *
+ * The bounds-checking logic built into user_regset_copyout and friends
+ * means that we can make a simple sequence of calls to map the relevant data
+ * to/from the specified slice of the user regset structure.
+ */
+static int vfp_get(struct task_struct *target,
+		   const struct user_regset *regset,
+		   unsigned int pos, unsigned int count,
+		   void *kbuf, void __user *ubuf)
+{
+	int ret;
+	struct thread_info *thread = task_thread_info(target);
+	struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
+	const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
+	const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
+
+	vfp_sync_hwstate(thread);
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				  &vfp->fpregs,
+				  user_fpregs_offset,
+				  user_fpregs_offset + sizeof(vfp->fpregs));
+	if (ret)
+		return ret;
+
+	ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+				       user_fpregs_offset + sizeof(vfp->fpregs),
+				       user_fpscr_offset);
+	if (ret)
+		return ret;
+
+	return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				   &vfp->fpscr,
+				   user_fpscr_offset,
+				   user_fpscr_offset + sizeof(vfp->fpscr));
+}
+
+/*
+ * For vfp_set() a read-modify-write is done on the VFP registers,
+ * in order to avoid writing back a half-modified set of registers on
+ * failure.
+ */
+static int vfp_set(struct task_struct *target,
+			  const struct user_regset *regset,
+			  unsigned int pos, unsigned int count,
+			  const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct thread_info *thread = task_thread_info(target);
+	struct vfp_hard_struct new_vfp;
+	const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
+	const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
+
+	vfp_sync_hwstate(thread);
+	new_vfp = thread->vfpstate.hard;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				  &new_vfp.fpregs,
+				  user_fpregs_offset,
+				  user_fpregs_offset + sizeof(new_vfp.fpregs));
+	if (ret)
+		return ret;
+
+	ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
+				user_fpregs_offset + sizeof(new_vfp.fpregs),
+				user_fpscr_offset);
+	if (ret)
+		return ret;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				 &new_vfp.fpscr,
+				 user_fpscr_offset,
+				 user_fpscr_offset + sizeof(new_vfp.fpscr));
+	if (ret)
+		return ret;
+
+	vfp_flush_hwstate(thread);
+	thread->vfpstate.hard = new_vfp;
+
+	return 0;
+}
+#endif /* CONFIG_VFP */
+
+enum arm_regset {
+	REGSET_GPR,
+	REGSET_FPR,
+#ifdef CONFIG_VFP
+	REGSET_VFP,
+#endif
+};
+
+static const struct user_regset arm_regsets[] = {
+	[REGSET_GPR] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+		.get = gpr_get,
+		.set = gpr_set
+	},
+	[REGSET_FPR] = {
+		/*
+		 * For the FPA regs in fpstate, the real fields are a mixture
+		 * of sizes, so pretend that the registers are word-sized:
+		 */
+		.core_note_type = NT_PRFPREG,
+		.n = sizeof(struct user_fp) / sizeof(u32),
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+		.get = fpa_get,
+		.set = fpa_set
+	},
+#ifdef CONFIG_VFP
+	[REGSET_VFP] = {
+		/*
+		 * Pretend that the VFP regs are word-sized, since the FPSCR is
+		 * a single word dangling at the end of struct user_vfp:
+		 */
+		.core_note_type = NT_ARM_VFP,
+		.n = ARM_VFPREGS_SIZE / sizeof(u32),
+		.size = sizeof(u32),
+		.align = sizeof(u32),
+		.get = vfp_get,
+		.set = vfp_set
+	},
+#endif /* CONFIG_VFP */
+};
+
+static const struct user_regset_view user_arm_view = {
+	.name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
+	.regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
+};
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+	return &user_arm_view;
+}
+
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
@@ -710,19 +811,31 @@ long arch_ptrace(struct task_struct *child, long request,
 			break;
 
 		case PTRACE_GETREGS:
-			ret = ptrace_getregs(child, datap);
+			ret = copy_regset_to_user(child,
+						  &user_arm_view, REGSET_GPR,
+						  0, sizeof(struct pt_regs),
+						  datap);
 			break;
 
 		case PTRACE_SETREGS:
-			ret = ptrace_setregs(child, datap);
+			ret = copy_regset_from_user(child,
+						    &user_arm_view, REGSET_GPR,
+						    0, sizeof(struct pt_regs),
+						    datap);
 			break;
 
 		case PTRACE_GETFPREGS:
-			ret = ptrace_getfpregs(child, datap);
+			ret = copy_regset_to_user(child,
+						  &user_arm_view, REGSET_FPR,
+						  0, sizeof(union fp_state),
+						  datap);
 			break;
-		
+
 		case PTRACE_SETFPREGS:
-			ret = ptrace_setfpregs(child, datap);
+			ret = copy_regset_from_user(child,
+						    &user_arm_view, REGSET_FPR,
+						    0, sizeof(union fp_state),
+						    datap);
 			break;
 
 #ifdef CONFIG_IWMMXT
@@ -736,7 +849,7 @@ long arch_ptrace(struct task_struct *child, long request,
 #endif
 
 		case PTRACE_GET_THREAD_AREA:
-			ret = put_user(task_thread_info(child)->tp_value,
+			ret = put_user(task_thread_info(child)->tp_value[0],
 				       datap);
 			break;
 
@@ -757,11 +870,17 @@ long arch_ptrace(struct task_struct *child, long request,
 
 #ifdef CONFIG_VFP
 		case PTRACE_GETVFPREGS:
-			ret = ptrace_getvfpregs(child, datap);
+			ret = copy_regset_to_user(child,
+						  &user_arm_view, REGSET_VFP,
+						  0, ARM_VFPREGS_SIZE,
+						  datap);
 			break;
 
 		case PTRACE_SETVFPREGS:
-			ret = ptrace_setvfpregs(child, datap);
+			ret = copy_regset_from_user(child,
+						    &user_arm_view, REGSET_VFP,
+						    0, ARM_VFPREGS_SIZE,
+						    datap);
 			break;
 #endif
 
@@ -784,38 +903,70 @@ long arch_ptrace(struct task_struct *child, long request,
 	return ret;
 }
 
-asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
+enum ptrace_syscall_dir {
+	PTRACE_SYSCALL_ENTER = 0,
+	PTRACE_SYSCALL_EXIT,
+};
+
+static void tracehook_report_syscall(struct pt_regs *regs,
+				    enum ptrace_syscall_dir dir)
 {
 	unsigned long ip;
 
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return scno;
-	if (!(current->ptrace & PT_PTRACED))
-		return scno;
-
 	/*
-	 * Save IP.  IP is used to denote syscall entry/exit:
-	 *  IP = 0 -> entry, = 1 -> exit
+	 * IP is used to denote syscall entry/exit:
+	 * IP = 0 -> entry, =1 -> exit
 	 */
 	ip = regs->ARM_ip;
-	regs->ARM_ip = why;
+	regs->ARM_ip = dir;
+
+	if (dir == PTRACE_SYSCALL_EXIT)
+		tracehook_report_syscall_exit(regs, 0);
+	else if (tracehook_report_syscall_entry(regs))
+		current_thread_info()->syscall = -1;
+
+	regs->ARM_ip = ip;
+}
 
+asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
+{
 	current_thread_info()->syscall = scno;
 
-	/* the 0x80 provides a way for the tracing parent to distinguish
-	   between a syscall stop and SIGTRAP delivery */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
+	/* Do the secure computing check first; failures should be fast. */
+	if (secure_computing(scno) == -1)
+		return -1;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
+	scno = current_thread_info()->syscall;
+
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_enter(regs, scno);
+
+	audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
+			    regs->ARM_r2, regs->ARM_r3);
+
+	return scno;
+}
+
+asmlinkage void syscall_trace_exit(struct pt_regs *regs)
+{
 	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
+	 * Audit the syscall before anything else, as a debugger may
+	 * come in and change the current registers.
 	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
-	}
-	regs->ARM_ip = ip;
+	audit_syscall_exit(regs);
+
+	/*
+	 * Note that we haven't updated the ->syscall field for the
+	 * current thread. This isn't a problem because it will have
+	 * been set on syscall entry and there hasn't been an opportunity
+	 * for a PTRACE_SET_SYSCALL since then.
+	 */
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		trace_sys_exit(regs, regs_return_value(regs));
 
-	return current_thread_info()->syscall;
+	if (test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }